1. Field of the Invention
The present invention relates to a device for discharging a gas from batteries for use on an electric vehicle.
2. Description of the Related Art
When batteries carried on electric vehicles are charged or discharged, they emit a hydrogen gas because the liquid electrolyte is electrolyzed. For safety precautions against accidental ignition of the emitted hydrogen gas, it is necessary to safely discharge the emitted hydrogen gas of its own accord or forcibly from the batteries.
In efforts to meet such a requirement, there has been proposed a device for discharging a gas from batteries on an electric vehicle as disclosed in Japanese utility model publication No. 1-34279, for example.
The proposed device has a pipe doubling as a solution supply pipe for supplying a battery solution or liquid electrolyte to the batteries and a gas discharge pipe for discharging a gas from the batteries. Specifically, solution supply chambers disposed above the respective batteries are connected in series with each other by the pipe which has an end vented to the atmosphere. The gas generated by the batteries is discharged from the batteries through the solution supply chambers and the pipe into the atmosphere.
One problem of the conventional device is that in the event of clogging of the pipe or a certain pipe failure, the gas is trapped in the pipe upstream of the clogged region of the pipe and remains undischarged from the corresponding batteries. The pipe is generally in the form of a soft hose such as a hose of synthetic resin or rubber, and hence can easily be clogged as by being flattened under pressure.